It’s not long after 3pm in Glasgow and the schoolchildren of Dalmarnock, in the city’s East End, are beginning to drift home. On the unprepossessing corner of Baltic Street, a little island of houses in a sea of empty tarmac in the lee of the Emirates Arena, they stop at a wooden gate and turn in to what looks like a piece of wasteland.

This is the Baltic Street Adventure Playground, a place that’s remarkable for a number of reasons. At Baltic Street there is not a roundabout or a seesaw in sight. Local children engage in messy and self-directed activities, such as swinging on tree ropes, wading in sand and mud or crawling through concrete pipes.

It’s an environment that’s as close to free play as you’re likely to find in any city street in the country, but it has been carefully and thoughtfully constructed to make it all possible. Play workers here, who are present during all official opening hours, encourage calculated risk and children learn their abilities and limits through experiment. Every day there is hot food: a supervised cookout on an open campfire.

But amongst the remarkable things about Baltic Street is that it’s in some sense an art work, kickstarted in 2013 by Glasgow’s Velocity project and designed by Assemble, 18 artists, architects and designers who have now been nominated for this year’s Turner Prize 2015 for work undertaken in Liverpool. As definitions of what artists are and do become ever wider, the London collective is the first group of its kind to be recognised by the annual award.

I’m here for that art: not just to see the playground, but to visit the bus that’s parked outside it. In the run up to the Turner Prize Exhibition, which opens at Glasgow’s Tramway on 1 October, the Travelling Gallery is touring the country with Eyes on the Prize. The exhibition is devoted to nine of the 22 Scotland-based artists who have been nominated for the Turner since its foundation in 1982, including Ian Hamilton Finlay, Christine Borland and Callum Innes.

The Travelling Gallery, and its longstanding curator Alison Chisholm, have long championed a wide range of contemporary art, driving the length and breadth of the country to schools and communities who don’t have access to such quality on their own doorsteps. For the occasion the bus has a new ‘wrap’ designed by Edinburgh graphic artist Mike Ingalls and, on a nationwide tour, there is a particular focus on Glasgow’s urban areas.

The selection is necessarily small. The emotional tone however is wildly variable: from the deadpan humour of a giant gnawed bronze bone by David Shrigley, to the near histrionic quality of Douglas Gordon’s video installation Spiral. Featuring kohl-rimmed eyes weeping to a song by Rufus Wainwright, the last time I saw this work by Gordon was in a massive installation during the opening week of the Sydney Biennale in 2014. I see no reason why the people of Dalmarnock, Orkney or Moray shouldn’t get a chance to see it in their own neighbourhood too. In Australia the work was on show in the grand quayside spaces of the Museum of Contemporary Art. By coincidence (or perhaps not) the MCA’s director Liz Ann Macgregor is a Scot whose first job was at the Travelling Gallery.

If there’s a clear theme in the exhibition, it is about image and trace, about remnants and fragments. The wallpaper by Glasgow’s Ciara Phillips grew out of the traces of ink left on a screen when making a print: the excess and accident becoming the centre of the work itself.

Lucy Skaer’s 7 lithographs entitled 15.04.13-21.04.13 are part of a series created from the original printing plates of the front page of the Guardian newspaper. In one dramatic week in 2013 Margaret Thatcher was buried. Skaer has altered the plates so only the faintest traces of history remain.

Outside in the playground change is afoot too. Work is ongoing to build what will become a fire shelter so that the kids can eat hot food in the wet days of winter too. At Baltic Street, one of the play leaders I meet has training in contemporary performance. She has no problem in understanding the playground as a work of art as well as a place to have an adventure. As she explains it’s a place that is created and recreated anew every day.

Some 200 kids are registered users of Baltic Street, although you don’t need to register to play there. As I prepare to leave three nine year-old girls in pristine school uniform are at the top of a high grassy hillock and have wedged themselves into a big plastic drainage pipe. With a bit of experienced shoogling they manage to propel it backwards down the hill. As they descend in somersaults two fly out of the sides and one, triumphantly, stays the course.

In the Travelling Gallery a pair of teenage girls, immaculate in black uniforms and serious personal grooming, are taking a tour of the bus. “What are youse doing here?” one of them asks. “We’re here because you are,” comes the instant reply.